Conventionally, the structure disclosed in "Techniques of Forming Superconductive Wiring Strip on Alumina Substrate", Electronic Parts and Materials, 1987 November, pages 89 through 92, published by Association of Industrial Investigation, is known as a typical example of the structure of the superconductive wiring strip of such an integration usage.
The superconductive wiring strip is formed on a substrate by using thick film printing techniques. In detail, a bulk solid of a superconductive ceramic material is pulverized into a powder of the superconductive ceramic material, a paste made from the powder is patterned on a high purity alumina substrate (which is known as "Fine Grained Alumina substrate" and abbreviated to "FGA") by using a screen printing technique, and, then, the patterned paste is sintered. In this way, the superconductive wiring strip is formed by using the screen printing technique.
However, since the wiring pattern is formed on the substrate by using the screen printing technique in the prior art process of forming the superconductive wiring strip, a problem is encountered in that miniature pattern geometries are hardly developed. For example, the screen printing technique is merely capable of producing conductive patters with a feature size as well as a tolerance fallen within a range between 50 microns and 100 microns.
It is therefore an object of the present invention to provide a process of forming a miniature wiring pattern of a superconductive material.